1. Field of the Invention
The present invention relates to an image forming apparatus provided with an automatic double-side unit for reversing paper and a manual paper feeding device.
2. Related Art Statement
In the image forming apparatus, there is an apparatus having a double-side printing function and a manual printing function. This image forming apparatus has the structure that in order to install machines and tools having both functions utilizing a limited space, an automatic double-side unit (ADU) for reversing paper in order to perform double-side printing is mounted on the side of the apparatus body encasing an image forming section, and a manual paper feeding device is mounted adjacent to the apparatus under the automatic double-side unit in order to perform printing by manual paper feeding.
Incidentally, in the image forming apparatus, jamming often occurs in the vicinity of the manual paper feeding device.
In the jam treatment in the vicinity of the manual paper feeding device, work of the jam treatment is difficult because the manual paper feeding device is located in an area for carrying out work for removing the jammed sheets.
In the past, in the image forming apparatus not provided with the automatic double-side unit, the art has been proposed in which by employing the structure in which a manual paper feeding device is provided on an opening and closing cover for carrying out jam treatment provided on the side of the apparatus body, and the manual paper feeding device can be opened to the apparatus body, and the structure in which when the manual paper feeding device is opened, pressure contact between a paper feeding roller and a separation roller of the manual paper feeding device is released, when the opening and closing cover is opened, the jammed sheet is easily removed from a carrier passage of the manual paper feeding device (for example, see Japanese Patent Application Laid-Open No. 2001/130757 Publication).
However, in many of the image forming apparatus having the automatic double-side unit and the manual paper feeding device, both machines and tools are arranged concentrically, that is, the automatic double-side unit and the manual paper feeding device are arranged adjacent to each other on the side of the apparatus body, different from the above-described image forming apparatus not provided with the automatic double-side unit. Particularly, they are arranged adjacent to each other. Due to the presence of the automatic both-side unit, it is difficult for the image forming apparatus having the automatic double-side unit to apply the structure for facilitating removal of the jammed manual paper in association with the opening and closing cover as in the above-described publication.
Therefore, in the image forming apparatus provided with both the automatic double-side unit and the manual paper feeding device, when the jam occurred in the vicinity of the manual paper feeding device is treated, the automatic double-side unit to be an obstacle is moved to expose the manual paper feeding device directly under thereof to outside, after which parts of the manual paper feeding device are operated to remove the paper jammed in the vicinity of the manual paper feeding device. Therefore, in the jam treatment, many works are demanded till arriving the jammed place, as compared with the image forming apparatus not provided with the automatic double-side unit. Particularly, it is hard to find the jammed paper around the manual paper feeding device. Moreover, since the opened portions are not many, it is difficult to secure the work space for carrying out the jam treatment. In addition, there is demanded the work which is troublesome and requires labor, such that the paper sandwiched between the paper feeding roller and the separation roller of the manual paper feeding device is pulled out, and therefore the jam treatment was considerably troublesome.